The invention relates to water-dilutable binders, to aqueous coating materials containing these binders and to processes for the priming or one-coat painting of plastics.
In order when painting plastics to achieve satisfactory adhesion of the applied coat or the applied coats it is necessary to pretreat the plastic surface, for example by flame treatment, corona treatment, plasma treatment or by etching with chromosulfuric acid and/or priming with special coating materials.
Pretreatment methods such as flame treatment, corona treatment, plasma treatment or etching with chromosulfuric acid are associated with technical effort and/or should be avoided on ecological grounds.
To prime plastics based on polypropylene, it is usual to employ coating materials which have the disadvantage that they include halogen-containing binders (cf. for example JP-A-256 556/1989).
EP-A-468 644 describes coating materials which are said to be also suitable for the priming of plastics. The preparation of the binders employed in these coating materials, however, requires monomers which can be obtained only with difficulty.
The technical object of the present invention is to provide water-dilutable binders and aqueous coating materials which contain these binders and which can be employed in processes for the priming or one-coat painting of plastics.